Abstract Core C The goals of Core C (Biostatistics and Data Management) are to provide expert biostatistical guidance in the design, conduct and analysis of research projects comprising the program project and to assist the clinical investigators in developing a reliable and accurate data management system. Core C will provide biostatistical support to the research projects at every stage of the research. Core staff will work with investigators to develop efficient designs and sample sizes that will give adequate power to address study objectives. For clinical studies, we will contribute to the design of case report forms that collect all required information in an unambiguous way. As studies proceed, Core staff will assist in reviewing project databases and monitoring the quantity and quality of data collected, and will suggest modifications to the design or analysis plan as appropriate. Core members will conduct correct and efficient data analyses, prepare any necessary graphs and tables, assist investigators with the preparation of presentations and manuscripts, and consult on the design of subsequent research. The work of Core C will interface with the Animal/Pathology Core, particularly with respect to study design, as animal studies are planned and executed. The Core C staff members have extensive experience supporting cancer research, with strong backgrounds in basic science, translational research and clinical trials in addition to being themselves researchers in statistical methods. With their many years of experience with the PDT group, they look forward to further collaborative opportunities for both applying existing methods and adapting or developing new methods as needed.